I am not a know-it-all or an owner of a 3.0L engine, but the I have heard the initial 1989 v-6 did not have "the problem". The 1990 and later engines did have the the problem because they used more health conscious/factory worker materials in the head gaskests.
More impotantly, if truck was repaired by a Toyota dealership, then you can track the work done by the truck's VIN.
If the headgasket is defective Toyota will replace it free of charge under their "silent recall" and they will give you a free rental car,if your local dealership refuses to honour the recall call another dealership and give them the VIN if that fails call the Toyota Regional Office for your area of the USA and they will give your local dealership 48 hours to comply.
Repairs tv's,vcr's,home/car audio out of my home
1985 Toyota 4-Runner,22R-E,W56,RN60LV-MSEK,rusted rear step/towing chrome bumper with 241 000 KM